Direct answer
Packaging classes are used to indicate the relative hazard level of some hazardous substances: I represents a high hazard, II represents a medium hazard and III represents a lower hazard. Packaging classes affect packaging performance, individual content limits and some operating requirements, but not all hazardous product categories use a packing class and cannot be judged by product names alone.
Three levels.
| Packaging Level | Relative level of risk | Basic relationships that can be marked with UN packaging performance |
|---|---|---|
| I | High | Level X is normally required, subject to the specification of the specific packaging |
| II | Medium | Eligible X or Y levels may be used |
| III | Lower | Eligible levels X, Y or Z may be used |
The term “lower” here is only a relative concept within the same classification system, which does not represent ordinary goods or may exempt dangerous goods from requirements.
Which goods may use packing classes
For flammable liquids of Class 3, substances of Class 4, substances of Class 5.1, Class 6.1, Class 8 and Part 9 entries may be assigned a packing class. The allocation may be based on flash points, primary boiling points, toxicity, corrosive rate or test results.
Class 1 explosives, Class 2 gases, Class 6.2 infectious substances, Class 7 radioactive substances, partially self-reactive substances and organic peroxides usually use other sorting or packaging mechanisms and cannot be forcibly applied to I, II, III.
What's the impact of packing class?
- Type of packaging and performance level available;
- (a) The permissible quantity of each package and in its entirety;
- (b) The limits applicable to passenger and cargo aircraft;
- (a) A limited or exceptional number of qualifications;
- Packaging instructions, sealing and documentation requirements;
- Conditions for partial warehousing, segregation and shipment clearance.
Common error zone
Is the “hazardous category III” a category 3 hazardous?
Nope. Category 3 is the hazard category for flammable liquids; Packing level III is the relative hazard level of certain hazardous products, and the two are different fields.
Can packing level III be used for general packaging?
It cannot be inferred from this. (a) The packing instructions, limits and special requirements for specific UN entries still need to be consulted; Where UN-specified packaging is required, it must be packaged in a manner that is satisfactory.
What if MSDS didn't write the packing grade?
Vendors should be required to update MSDS or provide a credible basis for classification. A packing class cannot be chosen for transport; Professional classification or experimental support is required when necessary.
Shipment clearance list
Key disaggregated data such as product concentrations, physical state, flashpoints or toxicity, individual packaging volumes and planned modes of transport are provided at the time of submission of MSDS. GENORDA will conduct preliminary feasibility checks in conjunction with specific UN entries and shipping channels.
Official References
- UN Model Regulations, Rev.24, Part 2 and Part 4
- IATA DGR, 67th Edition (2026)
- IMO IMDG Code, Amendment 42-24
This paper does not replace the official classification. Packaging levels, modes of packaging and transport limits shall be subject to current applicable rules and carrier audits.